impressions on ghc-6.4

Serge D. Mechveliani mechvel at
Thu Jun 9 06:47:28 EDT 2005

On Thu, Jun 09, 2005 at 10:29:25AM +0100, Simon Marlow wrote:

> 5.02 is parsed as 5.2 by the Version parser:
> > readP_to_S parseVersion "5.02"
> [(Version {versionBranch = [5], versionTags = []},".02"),(Version
> {versionBranch = [5,2], versionTags = []},"")]
> so I'm not sure what you're referring to here.  Could you give a
> concrete example?

Ah, I see:  "sequence of natural numbers separated by dots".
So, the community needs to consider "ghc-5.02" and "ghc-5.2" as 
equivalent. As to me, I would not complain. I do not know, people 
may do.

On memory expense

> A difference of 2.5Mb is really very small.  If you could show that the
> space usage is linear in one case and flat in another, then we have a
> problem.

But a ratio   2600 K / 200 K  for n = 55000  is not so small.

I never tested this, but what if in this mergeSort-like example the
space sizes are 
                     space.6.4(n) = 13*space.5.02(n) 

(which has the above ratio for n = 55000)

Serge Mechveliani
mechvel at

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